Peter Abraham is right to be asking the question, because even the average fan at the game last night was asking the same question: who goes to the pen when Matsuzaka returns? My suspicion is that his answer – Wakefield – is also correct.

And to his credit, he looked at the issue from a number of angles. I wish, however, that he’d gone just a bit further with metrics he used. So let’s do that here.

Buchholz easily wins if ERA’s the metric, 1.80 to 6.38, but as Abraham noted ERA doesn’t tell the whole story. So let’s look at FIP, which normalizes the ERA to account for variances in league, defense and so on. Buchholz’ FIP is 4.51, which certainly feels more like how he’s pitched. Wakefield, meanwhile, is at 4.54. Translated, this indicates that Buchholz may have gotten a bit lucky, Wake a bit unlucky. And that even adjusting for luck, Buchholz has pitched more effectively. The ratios are a bit more mixed: Buch has the edge in K/9, 7.20 to 5.40, but Wake is walking fewer at 3.44 BB/9 to 5.40.

One could make the argument, I suppose, that Wakefield has been profoundly unlucky when it comes to BABIP. In 2010 hitters are averaging .340 on balls in play. Given that his career average is .282, they’re hitting about fifty points better than they should.

But while that’s likely to regress to the mean, resulting in a statistical improvement, it’s not likely enough to make him a better choice than Buchholz. According to the stats, anyway.

Because as much as it might be easy to run a club by the numbers, Francona – bless him – knows better than that. There are a myriad of factors that will go into his decision, the numbers being but one of them. I think he’ll end up with Wake going to the pen, but it’s not as if the situation is cut and dry so there’s room for disagreement.

All that I wanted to do here was add some context to Abraham’s statistics argument, which seemed to me to be lacking.